Fire suppression is generally based on removing one or more of the three ingredients needed for most fires to burn. These ingredients include fuel, oxygen and heat. Together these ingredients make up portions of what is commonly referred to as the fire suppression triangle. If one or more of these ingredients can be removed, combustion will be unable to be sustained.
It is commonly recognized that water is one of the best agents to extinguish fires. In sufficient quantities, water can extinguish the fire by interrupting the fire's chemical chain reaction. Water does this by either removing the necessary amount of heat required to sustain combustion or by displacing a sufficient amount of oxygen from the fire thereby interrupting the chemical chain reaction. In most municipal fire suppression settings, water is typically readily available at a cost reasonable for extinguishment. Even when water is available to put out a fire, water does have some drawbacks. These include moderate viscosity (internal resistance to flow and to penetrate burning substances), a high surface tension, minimal retention capability (will quickly be affected by gravity and drain off substances), and water can evaporate relatively quickly.
To minimize water's drawbacks various additives may be introduced into the water to improve the water's firefighting capabilities. Adding foam producing solutes and compressed air to water can be used to create compressed air foam, which is known to improve the firefighting properties of water. Compressed Air Foam Systems (CAFS) use a synthetic detergent derivative as a foaming agent. A CAFS typically uses a water pumping system in which a foam solution is added to the water and an additional air compressor system that injects air into the solution to generate the foam. The air compressor also provides energy, which propels compressed air foam farther than aspirated or standard water nozzles.
Scientifically, CAFS impedes all three sides of the fire triangle simultaneously. The foam blankets the fuel, thereby reducing the fuel's capacity to react with a source of oxygen. The CAFS solution adheres to surfaces, more readily aiding in rapid reduction in heat. Also, the foam creates an insulation barrier shielding the fuel source from radiant energy.
The implementation of a CAFS usually requires expensive equipment. The typical cost of a CAFS ranges between $25,000 and $40,000 per installation each time a new firefighting apparatus is purchased. These costs are driven by hardware, such as an added compressor. Additional costs are required when retrofitting existing firefighting apparatus. The average lifespan of a fire fighting apparatus in the United States is fifteen years with twenty years not being unusual. Jurisdictions will typically not spend the money and time to retrofit the existing fleet of firefighting apparatus, which requires both taking the apparatus out of service for a period of time and spending money to add a CAFS capability to an apparatus. Given a life span of 15 years, a fire fighting apparatus which is purchased in 2014 without CAFS would probably not be upgraded or replaced until 2029.
It would therefore be of benefit to have a simpler, less expensive CAFS that could be fitted directly onto current firefighting equipment. The current invention provides for such a simple, inexpensive attachment device that integrates with current pressurized water sources to create compressed air foam for improved firefighting.